Chisel.



UNITED STATES FATENT @FFTQFL.

CHARLES W. THOMPSON AND FREDERICK A. GREARSON, OF BAR/BE, VERIIIONT.

CHISEL.

To all whom it may concern Be it known that we, CHARLES N. THOMP- soN and F REDERIOK A. GREARSON, citizens of the United States, residing at Barre, in the county of lVashington and State of Vermont, have invented new and useful Improvements in Chisels, of which the following is a specification.

This invention relates to bush hammers or chisels and has for an object to provide a tool of this character wherein the cutting bits will be positively held to the stock by means which will be so constructed that they can be quickly detached from the stock as desired.

In the drawing forming a portion of this application and in which like letters of reference indicate similar parts in the several views :Figure 1 is a side view of the tool. Fig. 2 is an edge view showing parts in sec tion. Fig. 3 is a section on line 33 of Fig. 1. Fig. 4 is a perspective view of the key. Fig. 5 is a perspective View of one of the benches. Fig. 6 is a perspective view of one of the bits. I

The tool comprises a shank 1 which is provided at one end with a relatively large substantially rectangular stock or head 2 having its opposite side faces provided with grooves 3 therein to receive the ribs 4 on the companion rocking wedge members 5. These wedge members are of a downwardly decreasing thickness and their outer surfaces have slidably fitted thereagainst similar wedge members 6. The wedge members 5 are slotted vertically at 7 and the members 6 are slotted in a similar manner as at 7 whereby the members 6 are adapted to slide across the outer surfaces of the members 5. The lower ends of the members 5 extend below the plane of the stock 2 so that they may be brought into flat contact with the outermost bits 8 so as to hold all of the bits positively grouped together. The wedge members 6 are provided below the plane of the members 5 with lugs 9 which bear against the outermost bits 8 whereby when pressure is brought to bear against the tool the resultant tendency will cause the wedge members to automatically cotiperate and combine to frictionally, and in wedge like manner engage against the bits to hold them properly associated with the stock of the tool. With a View to holding the bits 8 against lateral relative movements on the cutting end of the stock we Specification of Letters Patent.

Application filed October 4, 1912.

Patented June 2a, 1913. Serial No. 723,922.

provide the key 10. This key is disposed against the bottom of the stock and its ends extend through the slots 7 in the members 5 and through the similar slots 7 in the wedge members 6. The outer ends of the key 10 are provided with heads 12 which present the relatively broad flat surfaces 13 which extend transversely to the plane of the slots 7 and which are engaged frictionally against the outer surfaces of the members 6. The bits 8 are provided in their upper edges with grooves 14 through which the key 10 extends. Now, from the construction described it is seen that under the force of the cutting bits againstthe material operated upon the members 5 and 6 will be moved relatively to force their automatic locking engagement against the bits. When it is desired to remove the bits the heads 12 on the key 10 may be struck by a suitable tool and thereby forced against the walls of the grooves 14 and against the walls 15 of the slots 7 to effect release movements of the members 5 and 6 to thereby bring them out of locking contact with the bits as is under stood.

In order to provide means by which the wedge members 5 and 6 may be locked against longitudinal movement with respect to each other when in engaging position, we have provided openings 16 in each of said wedge members in alinement with the slots 7 and 7 respectively, therein. We have also provided the stock with recesses 17 in its side faces which are adapted to aline with the openings 16 inthe wedge member 6 when they are in their secured engaging position and which are adapted to receive the inbent extremities 18 of a locking member 19 so as to effectively prevent longitudinal movement, or slipping of the wedge members in respect to each other. This locking memher is provided with a manipulating or handle portion 20 and is adapted to embrace the wedge members when in its operative position, it being adapted to have its arms 21 expanded when it is desired to draw its inbent locking extremities from engagement with the wedge openings and the stock recesses, due to the fact that the said locking member is constructed of resilient material. It is to be further understood that the wedge members 5 and 6 are adapted to be interchangeable in their positions with relation to the stock and bits, because of the identical constructi0n of both sides of the wedge members, thus rendering it necessary to pro- 1. A bush hammer comprising a stock, substantially wedge like members mount-ed for rocking movement on the sides of the:

stock and having bit clamping portions dis posed below one end of the stock, bits int-erposed between the members, second wedge members slidable against the first members and having port-ions engaged against the bits, and a key extending through the wedge members and having flat head portions -frictionally bearing against the outer surfaces of the said second members.

2. A bush hammer comprising a stock, substantially wedge like members mounted for rocking movement on the sides of the stock and having bit clamping portions disposed below one end of the stock, bits interposed between the members, second wedge members slidable against the first members and having portions engaged against the bits, and a key extending through the wedge members and through the bits, and having flat head portions frictionally bearing against the outer surfaces of the said second members.

8. A bush hammer comprising a stock, substantially wedge members mounted for rocking movements on the stock and having bit clamping portions extending beyond the end of the stock, bits interposed between said portions and provided with grooves therein, a key extending through the grooves in the bits and through the said members,

second substantially wedge members slidable against the first members and adapted to force the said first members into locking contact with the bits and having portions below the plane of the first members extending in the direction of the bits and contacting therewith, and flat heads formed on the ends of the key and frictionally bearing against the outer surfaces of the said. second members.

4. A bush hammer comprising a stock, substantially wedge-like members mounted for rocking movement on the sides of the stock and having hit clamping portions disposed below one end of? the stock, bits interposed between the said members, a second. set of wedge members slidably mounted against the first set of members and having hit engaging portions, a key extending through the wedge members and having flat head portions frictionally bearing against the outer surfaces of the said second set of wedge members, and means by which the said second set of members may be locked with respect to the stock when in engaging position.

5. A bush hammer comprising a stock, substantially wedge-like members mounted for rocking movement on the sides of the stock and having bit clamping portions disposed below one end of the stock, bits interposed between the said members, a second set of wedge members slidably mounted against the first set of members and having bit engaging portions, a key extending through the wedge members and having flat head portions frictionally bearing against the outer surfaces of the said second set of wedge members, and detachable means for locking the second set off: wedge mem bers in engaging position.

In testimony whereof we afiix our signatures in presence of two witnesses.

CHARLES W. THOMPSON. FREDERICK A. GREARSON.

Witnesses Emma R. DAVIS, GEO. L. MORRIS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Eatcnts, Washington, D. U. 

